Injen SES1577 SES Axle Back Exhaust for 2006-2011 Honda Civic Si 2.0L Polished

Vehicle Fitment

• 2006-2011 Honda Civic Si (FA5 Sedan, FG2 Coupe | L4-2.0L K20Z3)

Fitment Notes

• Compatible with the 8th-generation Honda Civic Si in both Sedan (FA5) and Coupe (FG2) body styles. Both share the same K20Z3 2.0L naturally aspirated engine and the same axle-back exhaust configuration.
• Does not fit non-Si Civic trims (DX, LX, EX, EX-L) equipped with the 1.8L R18A1 engine - those models use a different rear exhaust configuration. For the 2006-2011 Civic Si with burnt titanium tips, see Injen SES1578TT.
• Axle-back installation - this system attaches at the rear axle flange and replaces the rear muffler and exhaust section only. The front pipe, catalytic converter, and mid-pipe are retained from the factory.
• No cutting or welding required. Bolt-on installation using factory mounting points and OEM-compatible stainless steel investment cast flange. Professional installation at a muffler or tuner shop is recommended for optimal fitment and alignment.
• Installed exhaust systems are non-returnable per Injen's policy.

Features

• Dyno-proven performance gains of up to 5 additional horsepower and 4 lb-ft of torque over the factory exhaust, verified on Injen's in-house dynamometer
• Full 60mm (2.375") 304 stainless steel mandrel-bent tubing maintains the tube's full inner diameter through every bend - eliminating the flow restrictions created by conventional press-bent exhaust piping
• Round JDM-style rear muffler (5.5" diameter body, 12" length) delivers Injen's signature aggressive exhaust tone - a deep, full sound with enough volume to be clearly heard without being intrusive
• Beautiful 4.0" polished stainless steel exhaust tip delivers a clean, premium show-quality rear fascia appearance that complements the Civic Si's sport-oriented styling
• Stainless steel investment cast flange ensures a fast, precise, leak-free connection to the factory mid-pipe at the axle - no exhaust leaks, no re-welding required
• 100% TIG welded construction - every weld is applied by hand for maximum joint strength, gas-tight seals, and professional-quality structural integrity throughout the entire system
• Premium stainless steel hardware and hangers provide secure, vibration-resistant mounting with long-term corrosion resistance
• Designed specifically for the K20Z3's exhaust flow characteristics - not a generic bolt-on adapted from another application but a purpose-engineered system tuned for this engine's back-pressure and power curve
• Handcrafted in Pomona, California, USA
• Protected by Injen Technology's 1-Year Warranty against defects in material and workmanship on exhaust systems

Specifications

• Part Number: SES1577
• Series: SES (Performance Exhaust)
• System Type: Axle-Back
• Application: 2006-2011 Honda Civic Si L4-2.0L K20Z3 (FA5 Sedan, FG2 Coupe)
• Tubing Material: 304 Stainless Steel
• Tube Diameter: 60mm (2.375")
• Tube Construction: CNC Mandrel-Bent
• Muffler Style: Round JDM-Style
• Muffler Body Diameter: 5.5"
• Muffler Body Length: 12"
• Exhaust Tip: 4.0" Polished Stainless Steel
• Flange: Stainless Steel Investment Cast
• Welding: 100% Hand TIG Welded
• Dyno-Proven HP Gain: Up to +5 HP
• Dyno-Proven Torque Gain: Up to +4 lb-ft
• Installation: Bolt-On, No Cutting or Welding Required
• Made in USA (Pomona, California)
• UPC: 843115013424
• Weight: 47.0 lbs
• Package Dimensions: 47" L x 19" W x 12" H
• Warranty: 1-Year Limited Warranty (exhaust systems)

Included Components

• 1x 60mm 304 Stainless Steel Mandrel-Bent Axle-Back Exhaust Pipe Section
• 1x Round JDM-Style Stainless Steel Muffler
• 1x 4.0" Polished Stainless Steel Exhaust Tip
• 1x Stainless Steel Investment Cast Flange
• 1x Complete Hardware Kit (stainless steel hangers, hardware, and fasteners)

Product Description

The Injen SES1577 is an SES Series axle-back exhaust system engineered specifically for the 2006-2011 Honda Civic Si in both the FA5 Sedan and FG2 Coupe body styles. It delivers dyno-proven gains of up to 5 horsepower and 4 lb-ft of torque over the factory exhaust by reducing back-pressure and improving exhaust flow velocity through its full 60mm 304 stainless steel mandrel-bent piping and purpose-designed round JDM-style muffler. As an axle-back system, the SES1577 attaches at the rear axle flange and replaces only the rear muffler and exhaust section - the factory front pipe, catalytic converter, and mid-pipe are all retained, making this one of the cleanest and most reversible exhaust upgrades available for the FA5/FG2 platform. For the same system with burnt titanium tips, see the Injen SES1578TT.

The round JDM-style muffler is the signature element of the SES1577's sound character. At 5.5" in diameter and 12" in body length, it produces a deep, full-bodied exhaust note that emphasizes the K20Z3's high-revving naturally aspirated character - particularly as the K20 climbs toward its 8,000 RPM redline through i-VTEC engagement. The tone is aggressive and clearly audible but avoids the drone and harshness that plagues many generic muffler replacements. Injen specifically dyno-tunes each exhaust system design rather than simply bolting on a high-flow muffler, which is what separates the SES1577's sound from off-the-shelf alternatives.

Construction quality is consistent throughout: every weld is hand-TIG welded from 100% 304 stainless steel, the flange is precision investment cast for a leak-free factory-compatible connection at the axle, and all hangers and hardware are stainless steel for long-term corrosion resistance. Installation is bolt-on at the rear axle flange with no cutting or welding required. Injen recommends professional installation at a muffler or tuner shop for optimal fitment, alignment, and clearance. Note that per Injen policy, all installed exhaust systems are non-returnable. Made in Pomona, California and covered by Injen Technology's 1-Year Warranty against defects in material and workmanship.